Deep Synoptic Array science I: discovery of the host galaxy of FRB 20220912A

Vikram Ravi, Morgan Catha, Ge Chen, Liam Connor, Jakob T. Faber, James W. Lamb, Gregg Hallinan, Charlie Harnach, Greg Hellbourg, Rick Hobbs, David Hodge, Mark Hodges, Casey Law, Paul Rasmussen, Kritti Sharma, Myles B. Sherman, Jun Shi, Dana Simard, Reynier Squillace, Sander Weinreb, David P. Woody, Nitika Yadlapalli, Tomas Ahumada, Dillon Dong, Christoffer Fremling, Yuping Huang, Viraj Karambelkar, Jessie M. Miller

Submitted on 16 November 2022


We report the detection and interferometric localization of the repeating fast radio burst (FRB) source FRB 20220912A during commissioning observations with the Deep Synoptic Array (DSA-110). Two bursts were detected from FRB 20220912A, one each on 2022 October 18 and 2022 October 25. The best-fit position is (R.A. J2000, decl. J2000) = (23:09:04.9, +48:42:25.4), with a 90% confidence error ellipse of ±2 arcsec and ±1 arcsec in right ascension and declination respectively. The two bursts have disparate polarization properties and temporal profiles. We find a Faraday rotation measure that is consistent with the low value of +0.6 rad m2 reported by CHIME/FRB. The DSA-110 localization overlaps with the galaxy PSO J347.2702+48.7066 at a redshift z=0.0771, which we identify as the likely host. PSO J347.2702+48.7066 has a stellar mass of approximately 1010M, modest internal dust extinction, and a star-formation rate likely in excess of 0.1M yr1. The host-galaxy contribution to the dispersion measure is likely 50 pc cm3. The FRB 20220912A source is therefore likely viewed along a tenuous plasma column through the host galaxy.


Comment: 10 pages, 7 figures, 2 tables, submitted to AAS Journals

Subjects: Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Astrophysics of Galaxies


Dedispersed total-intensity dynamic spectra for bursts 1 (left) and 2 (right) detected with the DSA-110 from FRB\,20220912A. Both bursts have been dedispersed to ${\rm DM}=219.46$\,pc\,cm$^{-3}$. Voltage data in one out of 16 sub-bands for Burst 2 were corrupted, resulting in the blanked data at the top of the band.